<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>源码对应电子书:百度"three.js 郭隆邦"</title>
    <style>
        body {
            margin: 0;
            overflow: hidden;
            /* 隐藏body窗口区域滚动条 */
        }
    </style>
    <!--引入three.js三维引擎-->
    <script src="http://www.yanhuangxueyuan.com/versions/threejsR92/build/three.js"></script>
    <!-- 引入threejs扩展控件OrbitControls.js -->
    <script src="http://www.yanhuangxueyuan.com/versions/threejsR92/examples/js/controls/OrbitControls.js"></script>
</head>

<body>
    <script>
        /**
         * 创建场景对象Scene
         */
        var scene = new THREE.Scene();
        /**
         * 创建网格模型
         */
        var geometry = new THREE.Geometry(); //声明一个几何体对象Geometry

        var p1 = new THREE.Vector3(0, 0, 0); //顶点1坐标
        var p2 = new THREE.Vector3(0, 100, 0); //顶点2坐标
        var p3 = new THREE.Vector3(50, 0, 0); //顶点3坐标
        var p4 = new THREE.Vector3(0, 0, 100); //顶点4坐标
        //顶点坐标添加到geometry对象
        geometry.vertices.push(p1, p2, p3, p4);

        // Face3构造函数创建一个三角面
        var face1 = new THREE.Face3(0, 1, 2);
        //三角面每个顶点的法向量
        var n1 = new THREE.Vector3(0, 0, -1); //三角面Face1顶点1的法向量
        var n2 = new THREE.Vector3(0, 0, -1); //三角面2Face2顶点2的法向量
        var n3 = new THREE.Vector3(0, 0, -1); //三角面3Face3顶点3的法向量
        // 设置三角面Face3三个顶点的法向量
        face1.vertexNormals.push(n1, n2, n3);

        // 三角面2
        var face2 = new THREE.Face3(0, 2, 3);
        // 设置三角面法向量
        face2.normal = new THREE.Vector3(0, -1, 0);

        //三角面face1、face2添加到几何体中
        geometry.faces.push(face1, face2);

        //材质对象
        var material = new THREE.MeshLambertMaterial({
            color: 0xffff00,
            side: THREE.DoubleSide//两面可见
        });
        //网格模型对象
        var mesh = new THREE.Mesh(geometry, material);
        scene.add(mesh); //网格模型对象添加到场景中

        // 辅助坐标系
        var AxesHelper = new THREE.AxesHelper(250);
        scene.add(AxesHelper);
        /**
         * 光源设置
         */
        //点光源
        var point = new THREE.PointLight(0xffffff);
        point.position.set(400, 200, 300); //点光源位置
        scene.add(point); //点光源添加到场景中
        //环境光
        var ambient = new THREE.AmbientLight(0x444444);
        scene.add(ambient);
        /**
         * 相机设置
         */
        var width = window.innerWidth; //窗口宽度
        var height = window.innerHeight; //窗口高度
        var k = width / height; //窗口宽高比
        var s = 150; //三维场景显示范围控制系数，系数越大，显示的范围越大
        //创建相机对象
        var camera = new THREE.OrthographicCamera(-s * k, s * k, s, -s, 1, 1000);
        camera.position.set(200, 300, 200); //设置相机位置
        camera.lookAt(scene.position); //设置相机方向(指向的场景对象)
        /**
         * 创建渲染器对象
         */
        var renderer = new THREE.WebGLRenderer();
        renderer.setSize(width, height); //设置渲染区域尺寸
        renderer.setClearColor(0xb9d3ff, 1); //设置背景颜色
        document.body.appendChild(renderer.domElement); //body元素中插入canvas对象

        // 渲染函数
        function render() {
            renderer.render(scene, camera); //执行渲染操作
        }
        render();
        //创建控件对象  相机对象camera作为参数   控件可以监听鼠标的变化，改变相机对象的属性
        var controls = new THREE.OrbitControls(camera, renderer.domElement);
        //监听鼠标事件，触发渲染函数，更新canvas画布渲染效果
        controls.addEventListener('change', render);
    </script>
</body>

</html>